I designed a pole cradle for back stretcher, poor mans solution, but...

I will update this design later with 35mm iron tube, for increased weight. Cost of iron tube is about 4 Eur per meter. With iron tube no weight container is needed.

Attach cradle to a 60x60 cm plate and use standard broom shaft (diameter 24mm, rounded at the end) to stretch your back.

I will also design a attaching cartridge that can be used as wight (sand filled) for to begin with. It is still too light.

UPDATE pole cradle v8 has additional reinforcement and modifed smaller holes.

original Finnish product https://www.venyy.com/kauppa